Keith R. Granger

Incorporating Organophosphate Alternative Insecticides Into Codling Moth Management Programs in Washington Apple Orchards

Azinphos-methyl (AZM) has been the most used insecticide in apple production in the United States since the late 1960s, primarily as a control for the key pest of apple ( Malus domestica Borkh.), codling moth ( Cydia pomonella L.). A decision by the EPA to phase out AZM by 2012 signals the end of this products use by tree fruit growers. In recent years, many new insecticides have been registered to replace AZM. These new insecticides have unique modes of action, but growers will need to change their traditional management practices to achieve the level of control they were accustomed to with AZM. Field trials were conducted from 2004 to 2008 to explore new application timings and strategies that incorporated insecticides with different modes of action and targeted life stages. It was apparent that new insecticides could not provide fruit protection superior to protection provided with AZM. However, strategies were developed that in many cases allowed equivalent control to the level of control experienced with a codling moth program based on AZM. The most successful strategies employed insecticides that targeted both eggs (ovicides) and larvae (larvicides). An insect growth regulator (ovicide) applied at the start of the oviposition period followed by two larvicide applications that targeted the peak egg hatch period provided fruit protection equivalent to the protection given by AZM applied twice.